Track battery percentage history; skip poll write when value unchanged

app.py

@@ -2,7 +2,9 @@ from flask import Flask, render_template, redirect, url_for, request, flash, abo
 from sqlalchemy import create_engine, func
 from sqlalchemy.orm import scoped_session, sessionmaker
 
-from models import Base, Battery, Device, CapacityTest, ChargeLog
+from datetime import datetime
+
+from models import Base, Battery, BatteryPctLog, Device, CapacityTest, ChargeLog
 
 
 def create_app(config_object="config"):
@@ -146,10 +148,15 @@ def create_app(config_object="config"):
                        .filter_by(battery_id=battery_id)
                        .order_by(ChargeLog.charged_date.desc(), ChargeLog.id.desc())
                        .all())
+        pct_logs = (db.query(BatteryPctLog)
+                    .filter_by(battery_id=battery_id)
+                    .order_by(BatteryPctLog.recorded_at.desc())
+                    .all())
         return render_template("battery_detail.html", battery=battery,
                                storage_locations=storage_locations,
                                capacity_tests=capacity_tests,
-                               charge_logs=charge_logs)
+                               charge_logs=charge_logs,
+                               pct_logs=pct_logs)
 
     # ------------------------------------------------------------------ #
     # Battery — edit notes
@@ -176,7 +183,16 @@ def create_app(config_object="config"):
         battery.charge_cycles       = _int("charge_cycles")
         battery.purchase_date       = f.get("purchase_date", "").strip() or None
         battery.storage_location    = f.get("storage_location", "").strip() or None
-        battery.battery_percentage  = _int("battery_percentage")
+        new_pct = _int("battery_percentage")
+        if new_pct != battery.battery_percentage:
+            battery.battery_percentage = new_pct
+            if new_pct is not None:
+                db.add(BatteryPctLog(
+                    battery_id=battery.id,
+                    percentage=new_pct,
+                    recorded_at=datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S"),
+                    source="manual",
+                ))
 
         db.commit()
         flash("Details updated.", "success")
@@ -251,6 +267,12 @@ def create_app(config_object="config"):
         if increment:
             battery.charge_cycles = (battery.charge_cycles or 0) + 1
         battery.battery_percentage = 100
+        db.add(BatteryPctLog(
+            battery_id=battery_id,
+            percentage=100,
+            recorded_at=datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S"),
+            source="charge",
+        ))
         db.add(ChargeLog(battery_id=battery_id, charged_date=date_val,
                          increment_cycles=increment, notes=notes))
         db.commit()